Apparatus for inductive heating of cylindrical members

ABSTRACT

The disclosure includes a pin heating device having a horizontal bed supporting a series of pins for heat-treating selected portions thereof. A high frequency heating coil is mounted with a horizontal axis aligned with a horizontal bed which extends to the opposite sides of the coil. A pair of quenching heads is provided at the discharge side of the coil. The bed includes opposed aligned rollers to support the pins and continuously rotate the pins as they pass through the coil and the heads. The rollers immediately adjacent to the coil have one or more circumferential grooves.

United States Patent [72} Inventor Paul F. Greis Thiensville, Wis. 21 AppLNo. 833,525

[22] Filed June 16, 1969 [45} Patented Jan. 19,1971

[7 3] Assignee Metal Processing Company Milwaukee, Wis. a corporation of Wisconsin [54] APPARATUS FOR INDUCTIVE HEATING OF CYLINDRICAL MEMBERS 10 Claims, 4 Drawing Figs.

[52] US. Cl 266/4, 2 1 9/ 10.67 [51] Int. Cl C21d 1/66 [50] Field ofSearch 219/1069, 10.71; 266/4E, SE, 8

[56] References Cited UNITED STATES PATENTS 2,506,425 5/1950 Journeaux 219/10.69X

Primary Examiner-Gerald A. Dost Attorney-Andrus, Sceales, Starke & Sawall ABSTRACT: The disclosure includes a pin heating device having a horizontal bed supporting a series of pins for heattreating selected portions thereof.

A high frequency heating coil is mounted with a horizontal axis aligned with a horizontal bed which extends to the opposite sides of the coil. A pair of quenching heads is provided at the discharge side of the coil. The bed includes opposed aligned rollers to support the pins and continuously rotate the pins as they pass through the coil and the heads. The rollers immediately adjacent to the coil have one or more circumferential grooves.

, ,PATENTEDJmemn "3.5562191 f INVENTOR. Paul F GrQis xwjwz, M M

I Attorneys BACKGROUND or INVENTION This invention relates to apparatus for inductive heating of successively conveyed cylindrical members.

Generally, in the induction heating of small metal members for raising them to a hardening temperature, an annealing temperature, or the like, the members pass vertically through an elongated induction heater. Althoughsuch devices have provided satisfactory heating, the devices are of a limited production capacity and require relatively complicated and expensive fixturing.

SUMMARY OF INVENTION The present invention is particularly directed to an" improved horizontal transporting means for heating selected portions of; tubular members at'a relatively high production rate. i

Generally, in accordance with the present invention, a high frequency heating coil means is mounted with a horizontal axis aligned with a horizontal transfer and support unit which extends laterally to the opposite sides of the high frequency induction coil means. The support unit to the opposite sides of the coil means defines an infeedside and a discharge side, respectively. A quenching means isprovided immediately adjacent the discharge side of the coil means and the transfer and support unit is constructed to continuously rotate the members as they pass through the induction heating coil means and the quenching means; A plurality of the members are disposed or placed on the infeed side of the support unit and a transfer means engages the outermost member to move the group of members longitudinally of the support and thereby move the series of pieces forwardly through the coil means. The transfer means is in accordance with the'preferred construction of the present inventionactuated through a suita ble stepped control to properly locateeach of the cylindrical members within the coils means for a selected time period and thereby provide heating of the member to the annealingtemperature.

In accordance with a particularly novel aspect of thepresent invention, the support is formed with laterally spaced roller means such that the cylindrical members rest on and between the upper surfaces of the adjacent roller means. The roller means are driven and continuously rotate the cylindrical member as it moves through the induction heating coil means. The roller means immediately adjacent to the coil or other induction heater means includes relatively small axially spaced rollers, each of which have one or more circumferential grooves. The small rollers are disposed immediately to the infeed side and the discharge side of the induction coil with the axis of the coil and the cylindrical members on the adjacent rollers in alignment. Each' member is, therefore, moved into location with respect to the induction heating coil-means and during the induction heating period is continuously rotated to provide an equal heat distribution within the member. The heated member is then pushed outwardly onto the discharge rotating rollers having the circumferential grooves. A quenching head means is mounted in alignment with the circumferentially grooved rollers and adapted to completely encase the continuously rotating heated members with a quenching fluid. The previously heated portion is thereby quenched while a different subsequent portion of the length of one member or a following member is being heated to the desired temperature for hardening, annealing, or the like. Thereafter, the quenched member is moved outwardly on the discharge side of the support for subsequent handling.

Applicant has found that the present invention provides a highly advantageous heat-treating apparatus for the inductive heating of successive tubular members on an induction basis.

BRIEF DESCRIPTION or DRAWINGS The drawing furnished herewith illustrates the best mode contemplated by. the inventor for carrying out his invention in roller support and more clearly showing a pin member in position to be heated; and I FIG. 4 is an enlarged sectional view taken generally on line 4-4 ofFlG. 2. 1

DESCRIPTION OF ILLUSTRATED EMBODIMENT OF INVENTION Referring to the drawing, and particularly to FIGS. 1 and 2, an inductive heating apparatus 1 for heat-treating of cylindrical metal members 2, such as link chain pins, is shown. The apparatus 1 generally includes a transfer'and support unit 3 extending in a horizontal, direction with aninduction heating coil 4 mounted generally in the center of the apparatus. The coil 4 has a horizontal axis aligned. with the supporting bed portion of the support unit 3. A plurality of the relatively short metal members 2 are adaptedto be mounted in end-to-end relationship -to the infeed end of the support unit 3. -A reciprocating pushrod 5 is mounted in alignment with the metal members 2 disposed on the support 3 to provide a transfer means for moving the members 2 through the coil 4. During the forward motion of the pushrod, the metal members 2- are moved longitudinally along the support unit 3 and through the coil 4' for purposes of raising selected portions thereof to a temperature. The plurality of the aligned metal members 2 are fed as a group to unit 3 by an infeed gravity chute 6 onto the aligned portion of the support unit 3.

As shown, most particularly in FIG. 3, the members 2 may be relatively short, solid metal pins which are to be heat treated in a predetermined pattern. In order to produce the desired positioning within the coil 4, the pushrod 5 is actuated in a proper sequence and at a desiredrate of travel. For example, in-the hardening of the central portion of a chain pin, the rod 5 is rapidly moved forwardly to position the leading end in the coil 4. A dwell is provided during which period the coil 4 7 establishes a dup heating of the aligned pin 2. The rod 5 is then moved forward at a predetermined rate and in accordance with the distance of the pin to be heat treated to heat the proper portion of thesteel pin within the coil 4. At the terininal end, a somewhat shortened dwell is provided to establish a sharp break off of the heated portion. The pushrod 5 is actuated through any suitable control to produce the desired heat pattern on a given member. In the illustrated embodiment, a piston-cylinder unit 7 is shown which may be provided with an automatic stepping control, such as a camoperated control for selectively supplying air to the opposite ends of the cylinder unit for longitudinallypositioning the rod 5 and,therefore, the members 2.

A pair of quenching liquid heads 8 and-9 are mounted on the discharge side of the induction coil 4 with the head 8 over the aligned pin 2 and head 9 beneath the aligned pin 2. The heads 8 and 9 establish a continuous stream of a quenching liquid which is applied to the heated cylindrical members 2 as they are transferred from the induction heating coil 4 onto the adjacent discharge side of the support unit '3.

The support unit 3 includes means, illustrated as a plurality of rollers, to continuously rotate the cylindrical members 2 about their own axis while they are positioned in the induction heating coil 4 and while they are aligned with the quenching heads 8 and 9. Applicant has found that this results in a very highly improved and satisfactory heat treating of the tubular or cylindrical members in a very rapid manner. The rolling support of the cylindrical members also allows the convenient and continuous movement of the members through the induction heating unit and with a minimum of force.

More particularly in the illustrated embodiment of the in- .y entipn, the support unit 3 is symmetrically formed about the coil 4. +T he infeed-end is described in detail, with corresponding elements to the discharge end identified by similar primed members.

The support uni, as shown most clearly in FlG 2, in-

' cludes a pair of similar elongated rollers and 11 which are laterally spaced with respect to each other to define a generallfchannel-shapedsupport therebetween upon which the members 2 are disposed. The rollers 10 and 11 may be formed of suitable steel or the like and span the infeed chute 6 to accept and support the series of end-to-end cylindrical members 2 which are successively fed from the chute 6. The rollers 10 and 11 are each similarly supported on shafts l2 and 13 secured to a supporting understructure 14 of the support unit 3. The shafts 12 and 13 extend longitudinally of the unit 3 and are rotatively mounted in suitable bearings 15 in the sup porting structure 14. A variable drive motor 16 is interconnected by a chain drive 17 to simultaneously rotate the shafts l2and 13 at a variable speed and in the same direction, as shown in FIG. 4. The shafts 12 and 13 and, therefore, the attached rollers 10 and 11 are shown rotated in a clockwise direction. This results in acounterclockwise rotational force applied by the support rollers 10 and 11 to the supported cylindrical member 2 as they move along the support unit.

The support rollers 10 and 1 l are spaced axially from the induction coil 4 and particularly the vertical center plane 4, therethrough by a distance somewhat less than the length of a member 2. Between the coil 4 and the rollers 10 and 11, pairs of special opposed wheel or rollers 18 and 19 are also fixed to ,the shafts 12 andl3 to similarly rotate." Each of the rollers 18 tioned within the induction heating coil 4 for purposes of raising it to the desired temperature and subsequently moved outwardly onto rollers 18 and 19' to the discharge side of coil 4.

The discharge side of the support unit 3 is generally constructed in the illustrated embodiment of the invention in the same manner as the infeed side and includes the pair of opposed grooved rollers 18 and 19' immediately adjacent the discharge side of the coil 4 and a pair of relatively elongated rollers 10' and 11' for transfer of the heated and quenched members The grooved rollers 18 and 19 forming a part of the quenching ortion of the assembly are preferably formed as two similar complementing roller halves similar to a pulley,

' with a spacer 21 therebetween. The spacer 21 permits controlling the width of the circumferential groove and thereby the introduction of the quenching liquid.

In the illustrated embodiment of the invention, the quenching heads 8 and 9 are similarly constructed with relatively boxlike outer nozzles or housing 22 having a plurality of discharge openings 23 aligned with and directed toward the vertical plane through the aligned grooved rollers 18 and 19' and in particular, toward member 2 supported on such rollers. The upper head 8 has the openings 23 in the bottom and the lower head 9 has the openings in the top to correspondingly direct the quenching liquid onto the member 2. Quenching liquid conduits 24 are interconnected to the nozzle 22 to supply a quenching liquid thereto under a desired pressure. As the members 2 are moved through the discharge side of the support unit 3, the quenching fluid is directed from the top and from the bottom onto the members 2. This. in combination with the continuous rotation of the members 2, has been found to provide a highly desirablequenching action.

ln the illustrated embodimentbf the invention, a quench tank reservoir 25 is shown mounted immediately below the quenching head'to collectthe excess quenching fluid as it falls from the quenching areas.

Although the induction heating coil 4can -.b. e .of any desired or suitable construction, applicant has found thatan unusually satisfactory result is obtained by applying a multjple turn, helical coil shown including four individual series-connected turns including an inner pair 26 and an outerpair 27m tinted in immediatelyadjacent relatiolziship and connectedflto each other by a suitable bonding material 28. In particular. applicanthas found that an unusually satisfactory bonding material is an epoxy sold by Minnesota Mining and Manufacturing under the mark Scotch Weld EC l386, although any other suitable material may be employed. The coil. 4 is connected to a suitably rated, high frequency power supply 29. I

In summary, the operators manually loads the chute 6 with a successively gravity dropping series-of the aligned members 2. As the pushrod 5 moves forwardly, thealigned series of members 2 moves through the inductionheating coil 4 in a stepped and controlled manner with each of the members 2 havinga selected portion aligned withirithe coil 4 for a desired time and passing therethrough at selected .rate. During this period, the induction heating" coil 4 is energized to rapidly raise the temperature of the aligned portion of the rotating member 2 to the required heat treating temperature. During the positioning of the member within the heating coil 4, it is continuously rotated as a result of the continuous rotation of the supporting rollers Is and 19. The rollers l0 and 11 impart an initial spinning or rotation to the members 2 such-that the relatively small surface engagement between the grooved rollers 18 and 19 and the members .ZWillrnaintain the-desired rotation thereof. After the required heating .time .ends,..the cylinder unit 7-is automatically actuatedsuch that .the pushro 5 and members 2 are movedforwardly at the desired rate and finally aligning the next required portion of the member within the coil 4 for a desired time. Simultaneously, the previously heated member 2 is moved onto the rotating rollers 18' and 19 into alignment with the quenching heads 8 and 9. The quenching heads 8 and 9 simultaneously supply quenching liquid to the rotating'member 2 from the top and bottom sides to insure the desired quenching action. The pushrod 5 operates in a periodic stepped manner until a complete series of members 2 taken from thechute 6 have been transferred forwardly toward and through the heating coil4. The rod 5 then retracts rapidly, allowing the next succeeding row of members 2 to move onto the support unit 3. The rod 5 then again moves forwardly to initiate a new cycle. The subsequent cycles permit continuous stepped heating of the members 2 in any desired pattern. 7

Applicant has .found that the present invention permits an unusually high production heat treating of solid steelpinsand the like with very accurate patterned heating.

1 claim:

1. A heat-treating apparatus for the successive "heating of similar cylindrical members, comprising ahorizontal support adapted to support said cylindrical members for axial transfer and having a rotating drive section -to positively and rapidly rotate said members about their own axis,,means to axially transfer said members along said support and through said rotating drive section, and a heating means mounted adjacent the support in thermally coupled heating relation to an aligned member to rapidly bring the member to a selected temperature, said rotating drive section being located to engage the member and positively rotate the cylindrical member during the alignment with the heating means;

2. The heat-treating apparatus of .claim 1, wherein said heating means is a high frequency inductive heating means having coil means mounted adjacent the .support in thermally coupled relation to an aligned member which is transferred through the coil.

axially along said support.

heating coiLmeans to apply quenching liquid to the tubular means and through 5. The heat treating apparatus of claim 2, wherein said support and drive section includes a first plurality of axially spaced drive rollers adjacent the coil means, a second plurality of axially spaced drive rollers aligned with the first'drive ro|- lers to define said support, means to rotate the rollers in the same direction, each of said rollers having at least one peripheral circumferential groove.

6. The heat-treating apparatus of claim 3, wherein said rotating drive section includes a plurality of laterally spaced roller means defining an upper supporting bed and means connected to rotate said roller means in the same direction.

7. The heat-treating apparatus of claim '6, wherein said drive section includes said plurality of axially spaced drive rollers located to the opposite ends of said coil means to maintain said rotating drive section to the opposite sides of the coil 1 means, and said quenching means aligned with the drive roling means includes a high frequency coil having at least two adjacent radially disposed turns with the coil axis aligned with members on said support, and a bonding material rigidlyinterconnecting the coil turns.

9. The heat-treating apparatus of claim2, wherein said support and drive section includes a first plurality of axially spaced drive rollers adjacent the discharge side of said coil means, a second plurality of axially spaced drive rollers mounted in opposed alignment with the first drive rollers to define the support for the members passing through the coil means, means to rotate the rollers in the same direction, each of said rollers having at least one peripheral circumferential groove, and a quenching liquid applicating means aligned with the rollers and applying quenching liquid to the top and hot tomof the member as it is moved from said coil means.

10. The heat-treating apparatus of claim 2; wherein said drive section includes a first plurality of axially spaced drive rollers adjacent the input side of the coil means and the output side of the coil means, a second plurality of axially spaced drive rollers mounted in opposed relation to the first drive rollers to define the support for the members, each of said rollers having at least one peripheral circumferential groove, opposed elongated rollers mounted in axially spaced aligned relation with the first and second rollers to the infeed side of the coil means, a feed chute means mounted to one side of the elongated rollers to simultaneously feed a plurality of longitudinally aligned cylindrical members laterally onto said elongated rollers, a reciprocating feed means mounted to move longitudinally of the support and having means to engage the trailing member and to push the plurality of members along said support and through said coil means, and means to rotate all of said rollers in the same direction. 

1. A heat-treating apparatus for the successive heating of similar cylindrical members, comprising a horizontal support adapted to support said cylindrical members for axial transfer and having a rotating drive section to positively and rapidly rotate said members about their own axis, means to axially transfer said members along said support and through said rotating drive section, and a heating means mounted adjacent the support in thermally coupled heating relation to an aligned member to rapidly bring the member to a selected temperature, said rotating drive section being located to engage the member and positively rotate the cylindrical member during the alignment with the heating means.
 2. The heat-treating apparatus of claim 1, wherein said heating means is a high frequency inductive heating means having coil means mounted adjacent the support in thermally coupled relation to an aligned member which is transferred through the coil.
 3. The heat-treating apparatus of claim 2, having a quenching liquid applicating means immediately adjacent the heating coil means to apply quenching liquid to the tubular member as it is moved from said heating means and through said rotating drive section.
 4. The heat-treating apparatus of claim 2, including lateral feed means to simultaneously feed a plurality of longitudinally aligned cylindrical members laterally onto said support, and a reciprocating feed means mounted to move longitudinally of the support and having means to engage the trailing member and to push the members along said support in a preselected stepped sequence to correspondingly locate the succeeding members within the coil means and the rotating drive section to simultaneously heat and rotate the member as it is moved axially along said support.
 5. The heat treating apparatus of claim 2, wherein said support and drive section includes a first plurality of axially spaced drive rollers adjacent the coil means, a second plurality of axially spaced drive rollers aligned with the first drive rollers to define said support, means to rotate the rollers in the same direction, each of said rollers having at least one peripheral circumferential groove.
 6. The heat-treating apparatus of claim 3, wherein said rotating drive section includes a plurality of laterally spaced roller means defining an upper supporting bed and means connected to rotate said roller means in the same direction.
 7. The heat-treating apparatus of claim 6, wherein said drive section includes said plurality of axially spaced drive rollers located to the opposite ends of said coil means to maintain said rotating drive section to the opposite sides of the coil means, and said quenching means aligned with the drive rollers to the discharge side of said coil means.
 8. The heat-treating apparatus of claim 2, wherein said heating means includes a high frequency coil having at least two adjacent radially disposed turns with the coil axis aligned with members on said support, and a bonding material rigidly interconnecting the coil turns.
 9. The heat-treating apparatus of claim 2, wherein said support and drive section includes a first plurality of axially spaced drive rollers adjacent the discharge side of said coil means, a second plurality of axially spaced drive rollers mounted in opposed alignment with the first drive rollers to define the support for the members passing through the coil means, means to rotate the rollers in the same direction, each of said rollers haVing at least one peripheral circumferential groove, and a quenching liquid applicating means aligned with the rollers and applying quenching liquid to the top and bottom of the member as it is moved from said coil means.
 10. The heat-treating apparatus of claim 2, wherein said drive section includes a first plurality of axially spaced drive rollers adjacent the input side of the coil means and the output side of the coil means, a second plurality of axially spaced drive rollers mounted in opposed relation to the first drive rollers to define the support for the members, each of said rollers having at least one peripheral circumferential groove, opposed elongated rollers mounted in axially spaced aligned relation with the first and second rollers to the infeed side of the coil means, a feed chute means mounted to one side of the elongated rollers to simultaneously feed a plurality of longitudinally aligned cylindrical members laterally onto said elongated rollers, a reciprocating feed means mounted to move longitudinally of the support and having means to engage the trailing member and to push the plurality of members along said support and through said coil means, and means to rotate all of said rollers in the same direction. 